2L the ODONATA FAUNA of BEAR MEADOWS, a BOREAL BOG in CENTRAL PENNSYLVANIA

li .2l Reprinted from the Proceedings of the Pa. Academy of Science, Vol. 42, 1968 THE ODONATA FAUNA OF BEAR MEADOWS, A BOREAL BOG IN CENTRAL PENNSYLVANIA H. B. WHITE, III Graduate Department of Biochemistry Brandeis University Waltham, Massachusetts 02154 G. H. AND A. F. BEATTY P. 0. Box 281 State College, Pennsylvania 16801 ABSTRACT In this report are compiled all known Odon Fifty-eight species of Odonata are re ata records for Bear Meadows through 1966. Since collecting has covered all months from corded as occurring at Bear Meadows, a May to November, the seasonal distribution of sphagnum bog in Central Pennsylvania many of the 58 species known from Bear Mea Seasonal distribution, relative abundance dows can be estimated. The data presented in and habitat preference are discussed. this paper are primarily the authors'; however, included are previously unpublished contribu tions of a number of collectors: J. Chemsak, INTRODUCTION C. Cook, T. W. Donnelly, S. W. Frost, J. Gil Bear Meadows is a 520-acre sphagnum bog lespie, J. G. Needham, R. A. Raff, J. M. Run nestled in the mountains of central Pennsyl ner and J. Schmidt. vania (Figs. 1, 2). It is 56 miles southwest of the nearest terminal moraine of Wisconsin LOCATION AND DESCRIPTION glaciation (1), the location of which makes it OF BEAR MEADOWS a very interesting place to study boreal organ Bear Meadows lies abov.t 7 miles south of isms at or near their southern limit of distribu State College in a protected mountain valley tion (2). Botanists are quite familiar with this 1824 ft above sea level. A semicircular moun bog because boreal species, such· as balsam fir tain ridge 500 ft above the valley surrounds and black spruce, grow here in association with the bog except for two openings to the north a flora more typical of Pennsylvania (3,4,5,6). east (Fig. 2). Access is by unpaved roads from Study of the dragonflies of Bear Meadows has U.S. Routes 322 and 545. revealed a pattern of association similar to that Palynological studies indicate that Bear found with plants. Meadows was formed 10,000 years ago when In the summer of 1931, James G. Needham drainage from the area was blocked, creating a of Cornell University, one of the preeminent shallow lake (6,7). The normal progression of workers on dragonflies, was a visiting professor bog formation has proceeded to the point where at the Penn State Nature Camp, located at forest has invaded much of the bog's original what is now Alan Seeger State Forest Monu area leaving at present a one and one quarter ment in Huntingdon County. He went with mile open strip along peat-stained Sinking a party of students and faculty to visit Bear Creek. On either side of this meandering Meadows, then difficult of access, because it stream, thick mats of sphagnum and peat sup was said to be an interesting place although port marsh grasses, sedges, leatherleaf and ex little-studied biologically. He caught speci tensive stands of high bush blueberries. The mens of Leucorrhinia hudsonica and Somato invading forest consists primarily of black chlora elongata, observed the unco=on tree spruce, hemlock, balsam fir, red maple, black Prunus alleghaniensis, and came back to camp gum and a dense undergrowth of rhododen effervescing with enthusiasm about the mar dron. Numerous seepage areas and springs velous boreal bog that he had seen, and declar along the edge of the bog feed Sinking Creek. ing that he would make a special study of its Despite logging operations in the late 19th dragonflies and write a paper on it. For some century (3) and the annual invasion of blue reason he never did, and this present contribu berry pickers, Bear Meadows has remained tion is a monument to the spirit and character generally unaltered. In 1965 Bear Meadows of James G. Needham. was proclaimed a National Forest Monument PENNSYLVANIA ACADEMY OF SCIENCE 131 Figure 1. Bear Meadow;;, view from near the bridge looking west. by Interior Secretary Udall, which should help RESULTS maintain this unusual habitat for future study The seasonal distribution, relative abundance and appreciation. and habitat affinities of the 58 species of PROCEDURE Odonata from Bear Meadows is summarized On most collecting trips to Bear Meadows it in Table 1. The fauna includes 7 species with was attempted to survey the species of Odon strong boreal affinities and 12 others with ata present and to estimate their relative weaker but definite boreal preferences. Ten abundance. A few sight records have been in species have a strong preference for streams cluded of species seen only on the wing but and are therefore associated with Sinking identified with certainty. Creek rather than the bog. Of the remaining Because of its ready access, the eastern end 29 species, 21 are frequent to common in cen of the bog adjacent to the bridge (Fig. 2) has tral Pennsylvania and do not show any spe received particular attention. This portion of cial preference for bog or stream environments. the bog contains a variety of sub-habitats and Eight species must be considered strays from is consequently populated by numerous species considerable distances. Their presence at Bear of Odonata. Surveys of the entire bog indicate Meadows is probably accidental. that collecting in the vicinity of the bridge is most productive and gives a reasonably repre Based on relative abundance, 29 or 50% of sentative sample of the species present. the species are rare. These are unlikely to be found during their flying season even when Data presented in this paper include those of N eedham's 1931 visit and several other early searched for. Twelve species are scarce, but collections, but over 80% of the records are the are usually collected in small numbers when result of work done since 1953. With the ex looked for. Ten species, observed consistently ception of data yielded by a collecting trip by without difficulty during their flying season, G. H. Beatty in June, 1945 (8) , none of the are termed common. The 7 species which are records in this paper has heretofore been re found in large numbers during their peak sea ported. son are classified as abundant. 132 PENNSYLVANIA ACADEMY OF SCIENCE <:-<,.. BEAR MEADOWS . ~o CENTRE COUNTY, PENNSYLVANtf ELEVATION 1824 FEET ~ ~BOG FOREST ~]BOG 1/4 MILE ·<t 0 DISCUSSION Somatochlora walshi Scudder Libellula quadrimaculata Linne Sphagnum bogs are among the less co=on Leucorrhinia hudsonica Selys habitat types in the Appalachians and their N ehalennia gracilis Morse Odonata faunas undoubtedly require much more study. This investigation of the Odonata In June, Gomphaeschna furcillata is an im of Bear Meadows has extended the known geo portant though not very conspicuous member graphical distribution of a number of species. of the Bear Meadows fauna. It is a cryptically It has also made the populations of other large colored species which blends with trunks of Pennsylvania bogs at Black Moshannon and dead trees on which it rests. The edge of the Tamarack, in Centre and Clinton Counties open meadow, especially where Sinking Creek respectively, more predictable since several of flows into the woods at the eastern end of the the species from Bear Meadows, which were bog, is the habitat of images of this species; unique records for the state, are now known the larvae have never been found at Bear from these other bogs. In the ensuing dis· Meadows though frequently sought. cussion, the Odonata population of Bear Mead Somatochlora elongata has been taken in few ows is divided into groups with similar ecologi Pennsylvania locations other than Bear Mead cal affinities. ows. This, however, is not the southernmost record since it has been reported from Mary The following species represent typical bog land (9), Virginia, and North Carolina (10). inhabitants and are part of the permanent Somatochlora elongata is not co=on at Bear breeding population. Meadows. Vlhen found, it is usually patrolling Gomphaeschna furcillata Say low over the stream, hovering frequently to ex Somatochlora elongata Scudder amine small coves along the bank, a flight Somatochlora tenebrosa Say pattern more characteristic of Aeshnids. PENNSYLVANIA ACADEMY OF SCIENCE 133 Since Bear Meadows is within the known probably part of the permanent breeding popu geographical range of Somatochlora tenebrosa, lation. its presence is of little distributional signifi Two species on this list are worthy of dis cance. It flies over the stream or hovers in cussion. Gomphus borealis has been collected sunlit clearings. on only 3 occasions. It is co=only and locally When Somatochlora walshi was first col abundant at Black Moshannon and Tamarack lected at Bear Meadows, it was the only Penn where it congregates on the bare ground, often sylvania occurrence and also the southern at the breast of beaver dams. Twice in this limit of its known distribution. Subsequently century beaver were introduced at Bear Mead it has been taken at the Black Moshannon and ows; however, they did not become established Tamarack bogs north of Bear Meadows but (3). Perhaps Gomphus borealis, along with still south of the Wisconsin Moraine. This spe the dead spires of drowned trees in the open cies is quite co=on some years. Occasionally meadow, is a vestige of short-lived beaver ac it flies over the stream, but more frequently tivity. it hovers over marshy pockets in the open Until recently (8) Epitheca canis was not meadow and sunny glades of the woodland known south of New York State. Studies in border. central Pennsylvania have shown this species The golden-flecked wings of Libellula quad to be relatively co=on and widespread al rimaculata are seen throughout June and July.

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